A trademark is a word, phrase, symbol, and/or design that identifies and distinguishes the source of the goods of one party from those of others. A service mark is a word, phrase, symbol, and/or design that identifies and distinguishes the source of a service rather than goods. Some examples include brand names, slogans, and logos. The term "trademark" is often used in a general sense to refer to both trademarks and service marks.  

Unlike patents and copyrights, trademarks do not expire after a set term of years. Trademark rights come from actual “use”. Therefore, a trademark can last forever - so long as you continue to use the mark in commerce to indicate the source of goods and services. A trademark registration can also last forever - so long as you file specific documents and pay fees at regular intervals

A trademark not only gives the trademark owner the exclusive right to use the mark but also allows the owner to prevent others from using a similar mark that can be confusing for the general public. When a person claims the rights to a particular mark, he or she is allowed to use "TM" (for a trademark) and "SM" (for a service mark) to designate that the mark is trademarked. The symbol "®" designates federal registration and can therefore only be used after the USPTO registers the mark, meaning the symbol cannot be used when an application is pending. In addition, the ® symbol may only be used with goods or services that were listed in the federal trademark application.